Decoration of Au Nanoparticles on MoS<sub>2</sub> Nanospheres: From Janus to Core/Shell Structure Le Zhou Hongwen Zhang Haoming Bao Guangqiang Liu Yue Li Weiping Cai 10.1021/acs.jpcc.8b01216.s001 https://acs.figshare.com/articles/journal_contribution/Decoration_of_Au_Nanoparticles_on_MoS_sub_2_sub_Nanospheres_From_Janus_to_Core_Shell_Structure/6099494 A flexible route is presented for the controlled decoration of the Au nanoparticles (NPs) on the spherical MoS<sub>2</sub> particles, just by dropping the HAuCl<sub>4</sub> aqueous solution into the hydrothermal reaction-induced MoS<sub>2</sub> colloidal solution at room temperature. In the absence of surfactants in the colloidal solution, it has been found that the obtained products are mostly the MoS<sub>2</sub>/Au Janus particles, in which the hemispherical Au particles are separately attached on the single MoS<sub>2</sub> spheres about 100 nm in size. The hemispherical Au particles are built of the ultrafine NPs (<10 nm) and comparable to the MoS<sub>2</sub> spheres in size. Further experiments have revealed that the existence of surfactants in the colloidal solution could significantly influence the distribution and decoration of Au NPs on the MoS<sub>2</sub> nanospheres. When the MoS<sub>2</sub> colloidal solution contains the nonionic or anionic surfactant, such as poly­(vinylpyrrolidone) and sodium dodecyl benzene sulfonate, in appropriate content, the addition of HAuCl<sub>4</sub> induces the Au ultrafine NPs highly uniformly attached or decorated on the MoS<sub>2</sub> spheres. The distribution of the Au ultrafine NPs on the MoS<sub>2</sub> spheres evolves from a dispersed decoration to the intact core/shell structure with the rising HAuCl<sub>4</sub> addition amount. However, the cationic surfactant could prevent Au NPs from decoration on the MoS<sub>2</sub> spheres and induce the self-agglomeration of Au NPs. The formation of MoS<sub>2</sub>/Au Janus particles is attributed to the aggregation growth of Au ultrafine NPs on the MoS<sub>2</sub> spheres, whereas the dispersed decoration of Au ultrafine NPs on the MoS<sub>2</sub> spheres is ascribed to the surfactant-induced uniform distribution of Au NPs. Interestingly, such decorated spherical MoS<sub>2</sub> NPs have exhibited a much higher surface-enhanced Raman scattering effect than the decorated MoS<sub>2</sub> nanoplates. This work presents a simple approach to the controllable decoration of Au NPs on the spherical MoS<sub>2</sub> particles. 2018-03-26 00:00:00 MoS 2 nanospheres MoS 2 NPs HAuCl 4 addition amount decoration Janus particles MoS 2 spheres HAuCl 4 surfactant-induced uniform distribution MoS 2 nanoplates sodium dodecyl benzene sulfonate MoS 2 Nanospheres hydrothermal reaction-induced MoS 2 MoS 2 particles ultrafine NPs